MOTM

At 2:35 AM -0400 2002/05/08, elhardt@... wrote:
>Ever since I built my MOTM I haven't liked the way the envelopes worked, yet
>I've never heard anybody else comment on them.  I'm wondering why not.  Is it
>just me that experiences the following problems?

I have four 800s and I tried to replicate the problems you are 
seeing. I patched the envelope into the FM input of a 300 so it was 
easier to hear the envelope. I tested using the Gate out from a 
Pro-One into the GATE input of the 800s. I didn't put anything into 
the TRIG input.

>1)  I patch up a sound and hit a key on the keyboard to trigger the sound and
>it sounds OK.  Then I start playing and all of a sudden the sound gets
>brighter and louder (I have envelopes going to both filter and amp).  This
>isn't right.  The envelope should not output higher voltages because I'm
>playing faster or more legato, yet it does.  I finally got around to scoping
>it and confirmed it.  With the exception of a little initial spike the ADSR
>outputs about 4 volts max.  Yet at certain settings if I play a fast trill I
>can push it up to about 6 volts.  Set A=0, D=6, S=7, R=4 and go into the a
>filter FM input and you'll see what I mean.

I used A=0, D=6, S=7, R=4 as you suggested but couldn't find anything 
bizarre; the envelopes behaved as I expected them to. However if I 
use A=0, D=10, S=10, R=10 and trill rapidly then I can get a 
sustained 6.4 volts out. I wasn't expecting that.

>2)  If the Sustain level is set way up to about 10, then the Decay acts like
>an Attack.  I can set the Attack to 0 and move the Decay around to get
>various length attacks.  It seems to control the attack time from the normal
>4 volts up to a higher voltage which is set by the sustain level.  Strange.

I get this one too. If I set A=0, D=10, S=10, R=0 then the envelope 
hits 4 volts almost instantly and then exponentially decays UP to 5 
volts over a period of around 15 seconds. If D=0 then the decay UP to 
5 volts is almost instantaneous.

>3)  I can set Attack to 0, Decay to 0, and Sustain to 10 to get plain organ
>type envelope, yet the attack portion is too soft.  It's impossible to get a
>hard solid sound at this setting.

Hmmm, mine sound snappy enough to me. I usually don't even use A=0 
because I find  it too snappy at that setting. Maybe there's some 
extra resistance in your Attack pot (it's not 0 ohms when fully CCW). 
If I set my Attacks to greater than 0 then my results are much closer 
to yours.

>And I haven't even gotten into the somewhat artificial sound of the envelopes
>either because I need to compare side by side with another synth.  But they
>almost sound linear instead of exponential (even though I'm sure they're not)
>and don't seem to have a really good bouncy and punchy quality I like.  But I
>need to compare to others before I can say for sure what's going on here.

They sound exponential to me. The only thing I miss is a really long 
attack time, 20 seconds would be nice. If I ever find some good 5 Meg 
log pots I might try replacing my Attack pots.

>
>I've never experienced these things with any of my other synths.  Am I the
>only one dealing with these issues?

I never noticed these 800 oddities until you mentioned it. I'm glad 
you brought it up, you're certainly not alone.